含锂水盐体系热力学性质研究——LiCl-MgCl_2-H_2O体系渗透系数和活度系数的等压测定  

Thermodynamics of Aqueous Electrolyte Solution Isopiestic Determination of Osmotic and Activity Coefficlents in LiCl-MgCl_2-H_2O at 25℃

作　　者：姚燕[1] 孙柏[1] 宋彭生[1] 张忠[1] 王瑞陵[1] 陈敬清[1] 

机构地区：[1]中国科学院盐湖研究所,西宁810008

出　　处：《化学学报》1992年第9期839-848,共10页Acta Chimica Sinica

基　　金：国家自然科学基金资助的课题

摘　　要：25℃下,用等压法测定了单盐水溶液(浓度范围分别为0.5—19.8mol·kg^(-1),0.3—6.0mol·kg^(-1))以及混合水溶液(离子强度范围为0.6—19.4mol·kg^(-1))的水活度和渗透系数,同时测定了LiCl的溶解度.该体系的实验等水活度线符合本工作推导出的Zdanovskii规则扩展式.用(Gibbs-Duhem方程和改进的Mckay-Perring方法计算了单盐和混合盐水溶液的潘度系数.由本实验获得的渗透系数拟合了Pitzer单盐和混合作用参数,检验了Pitzer方程对该体系渗透系数、活度系数和溶解度预测的适用性,用Pitzer方程取本工作得到的参数计算的溶解度与文献实验值基本一致.The osmotic and activity coefficients of aqueous mixtures of LiCl and MgCl_2 in the range low concentration to near crystallization limits and the solubility of LiCl in water have been measured by using the isopiestic method at 25℃. The experimental iso-water activity lines obey extended Zdanovskii rule well. The mean activity coefficients of LiCl and Mg01_2 in pure and mixing solutions were obtained from the osmotic coefficients by Gibbs-Duhem equation and Mckay-Perring method respectively. The parameters of Pitzer's model were evaluated from present measurements by using multiple regression analysis. The standard deviations between the calculated and experimentally determined osmotic coefficients and comparisons of the activity coefficients calculated by Pitzer's equation with Mckay-Perring method were reported. The predicted solubilities for the system studied using Pitzer's approach were shown to be in reasonable agreement with experimental results from references.

关 键 词：锂水盐体系 渗透系数 活度系数 

分 类 号：O614.111[理学—无机化学]